The fact is that the Muslim Brotherhood and its various offshoots represent a threat to everyone in the region:
But the Obama administration (and establishment Republicans like John McCain) insist that America must support democratically-elected Islamist governments. That is deeply misguided. The Muslim Brotherhood is about as democratic as the Nazi Party, which also won a plebiscite confirming Adolf Hitler as leader of Germany. Tribal countries with high illiteracy rates are not a benchmark for democratic decision-making.
The Saudi monarchy fears that the Brotherood will overthrow it (not an idle threat, since the Brotherhood doesn't look like a bad choice for Saudis who aren't one of the few thousand beneficaries of the royal family's largesse;
The Russians fear that Islamic radicalism will get out of control in the Caucasus and perhaps elsewhere as Russia evolves into a Muslim-majority country;
The Chinese fear the Uyghurs, a Turkic Muslim people who comprise half the population of China's western Xinjiang province.